Spiders are believed to have been in existence for more than 2 million years. Of the 40,000 known spider species, 3,400 can be found in North America.
Typically mistaken for insects, spiders are actually a member of the arachnid family, making them distant relatives of ticks and scorpions. Although all spiders bite, most do so only when they feel threatened. Arachnophobia, or the fear of spiders, is a prevalent phobia. As many as 50% of women and 20% of men are thought to have arachnophobia.
What do spiders look like?
A spider’s body consists of an abdomen, cephalothorax, eight six-jointed legs, and an exoskeleton. Most spiders have eight eyes which, along with the mouth, fangs, brain, stomach, and glands, are located in the cephalothorax. The spider’s spinnerets, which produce silk used to create webs, are located at the back of the abdomen. Spiders don’t have ears. Rather, their legs are covered with hairs that sense vibrations and smells.
Spiders vary in color and size depending on species. The body of the largest spider in the world, the Goliath bird-eating tarantula, can grow to one foot, though most spiders in the United States are 1/4” to 1” in length, with females usually larger than males.
After mating, female spiders create a sac filled with as many as a thousand eggs. These eggs hatch into spiderlings, which then grow into adults. Spiders shed and replace their exoskeleton multiple times – a process called molting – until they have reached full size. Female spiders in the United States typically live 1-3 years, while male spiders generally die within a few months.
What are the unique characteristics of spiders?
All spiders have the ability to spin silk which they use to create webs. Spider silk strands are made of protein and are considered to be the strongest natural fiber, able to withstand more stress proportionally than steel. However, not all spiders build webs. Some, including the Carolina wolf spider, live on or below ground.
What are the habits of spiders?
Spiders prey on insects, small animals, and other spiders; they generally do not eat plant materials. Many spiders rely on their webs to entrap their victims, while others are predatory, going out in search of their next meal. While spiders are not attracted to light, many of the insects they eat are, so spiders may be found near light sources.
Spiders are cold-blooded, which means they are comfortable in cooler weather and not inclined to seek warmth. In cold weather, they can become more dormant, but they can easily survive in below-freezing temperatures.
Where are spiders commonly found?
Spiders can be found just about anywhere. They tend to like hidden areas that are quiet and close to food and water sources. Indoor spiders can be found in old boxes, closets, shelves, basements, storage areas, garages, and anywhere else there is clutter. Outdoor spiders often take up residence in piles of wood, under rocks and debris, and in vegetation and wooded areas.
What are the risks of spiders?
While spiders can be beneficial – eating insects and other pests – some species can also be harmful to people and animals. Spider fangs emit venom which, depending on the type of spider, can produce symptoms ranging from very mild to lethal. Possible symptoms of a spider bite include swelling, skin lesions or welts, rash, itching, blistering, and pain around the bite area. Spider bites can also trigger allergic reactions, difficulty breathing, muscle pain or cramping, nausea and vomiting, fever, sweating, and headaches. In rare cases, spider venom can also cause the tissue around the bite to die, paralyze the nervous system, or result in death.